PROJECT SUMMARY (See instructions); Project 5: Stationary Breast Tomosynthesis Breast cancer is the second most common cancer type among women. Over 10% of women develop breast cancer during their lifetimes and 30% to 40% of these patients die from the disease, Eariy detecfion is viewed as the best hope to decrease mortality. Full-field digital mammography (FFDM) is the current gold standard for eariy detecfion but has it limitations. Digital breast tomosynthesis (DBT), a 3-D imaging technique. Is generally considered to be the next generation screening device with the potenfial for improved performance compared to FFDM. In the U.S., DBT scanners from 3 leading commercial vendors are in advanced stages of clinical trials. Recent clinical studies have shown that DBT, while having better detection capability for masses compared to FFDM, suffers from lower sensitivity for micro-calcifications (MC) which is critical for eariy cancer identification. The low MC detectability is attributed mainly to the low image resolufion due to mofion blurring of both the patient and the x-ray source during the relatively long scanning fime. The goal of this project is to develop a novel stationary DBT (s-DBT) technology that has the potential to improve our capability for eariy detection of human breast tumors. The key enabling technology is the carbon nanotube (CNT) based multi-beam field emission x-ray (MBFEX) that was pioneered by our team. During the first CCNE program, we proposed the s-DBT concept and demonstrated the possibility of construcfing a s-DBT scanner with significantly increased scanning speed and spafial resolufion compared to the current DBT technology. Our hypothesis is that the high spatial resolution will improve the sensitivity for both masses and micro-calcifications. In addition, the fast scanning speed will reduce patient discomfort due to prolonged compression. For this project we will develop a clinical-test ready prototype s-DBT system and validate its performance through phantom measurements and reader studies. The research will be carried out in close collaboration with Hologic, a market leader in women's healthcare and one ofthe major developers of the DBT technology.